Crown block



June 12, 1928.

E. o. BENNETT GROWN BLOCK Filed Dec. 11, 1923 2 Sheets-Sheet OOOQ M i w n Q i l 11...; 4 M z x 5 v 7 m j A "i ATTORNEY/51 June 12, 1928. 1,673,346

' E. o. BENNETT GROWN BLOCK Filed Dec. 11, 192:5 2 Sheets-Sheet 2 F 4-.. 4/ L 40 g 5 fig 5 /6 r 60 /8 v 27 6/ 76 ,2 k I r-/5 55 47 48 50 I ill I J o- I I M77012: [aw/N 0 5-NE f7;

loam wt v Patented June 12, 1928.

UNITED STATES PATENT oFncs.

EDWIN O. BENNETT, OF HAYWOOD, CALIFORNIA, ASSIG-NOR TO EDISCO STEEL IPROID- UCTS COMPANY, A CORPORATION OF CALIFORNIA.

CROWN BLOCK.

Application filed December 11, 1923. Serial No. 679,917.

This invention relates to oil well drilling equipment and relates particularly to the arrangement of sheaves placed at the top of the derrick to form a block for the hoisting of ropes and cables.

In the present form of well drilling equip ment, a crown block is employed which is equipped with an arrangement of sheaves whose axes are parallel to the axes of rotation of the band wheel, the bull wheel, and the calf Wheel. The opening in which the crown block is placed is generally five feet square and the sheaves are distributed through this area, certain of these sheaves being devoted to different purposes; some of them being arranged to receive the separate turns of rope from a suspended multiple sheave tackle block and other of the sheaves being adapted to receive hoisting ropes such as the sand line and cat line. lVith the arrangement now employed, the tackle sheaves are separated a considerable distance apart, thus causing the ropes to diverge as they extend upwardly from the suspended tackle block in. which the sheaves are placed close together. lVith this arrangement of rigging the tackle block, the height to which the suspended block may be lifted ranges between five and ten feet less than the height of the crown block from the derrick floor, owing to the acute angular divergence of the cables when the suspended member is in raised position. This angular disposal of the tackle ropes has the tendency of causing the outer ropes to come off the outer sheaves of the crown block if care is not exercised in limiting the height to which the suspended block is raised. A particular disadvantage in the present type of crown block is that the various rope sheaves are not centralized with the vertical axis of the derrick and therefore the pull exerted by hoisting ropes is not concentric with the well ca ing which is situated substantially in the center of the derrick floor.

It is an object of the invention to provide a crown block in'which the single rope sheaves such as employed for light hoisting are radially disposed relative to the central axis of the derrick and are so positioned that the ropes extend downwardly in the center of the derrick.

It is a further object of the invention to provide a stationary tackle sheave arrangement consisting of sheaves which are. arranged close together so that the ropes from the suspended tackle block will be substantially vertical and parallel throughout all the positions ot' the suspended member, thus permitting the raising of the movable block to the extreme top of the derrick.

It is a further object of the invention to provide a stationary tackle sheavcarrangement which is mounted above the single rope sheaves and is so arranged that the ropes which extend downwardly therefrom will clear the lower sheaves and the supporting members. This stationary tackle sheave arrangement is also centralized with the axis of the derrick so that the suspending block will hang in position directly above the well OPQIIIIIO.

In districts where rotary drilling is extensively practiced, the rotary draw works or driving gear is placed in a position to the side of the bull wheel and calt wheel. This placement of the draw works brings the axis of rotation of the draw works drum on a plane perpendicular to the rotational axes of the sheaves in the crown block. It is customary to lift heavy weights such as casing and drill pipe from the draw works by use of the multiple rope tackle. In accomplishing this with the present form of crown block, the end rope which leads to the draw. works drum is carried angularly from the end crown block sheave which causes rapid wear on the flange of the sheave and also considerable wear on the cable. 'lVhen the flange has become worn down due to. the wearing action of the. rope, breakage occurs causing the rope to ride ofl the sheave and to become caught in the crown block structure,

causing considerable delay and often injurw ing the cable.

In my invention, the stationary tackle sheave arrangement is disposed above the single rope sheaves and with its axis of the rotary draw works drum, thus placing the axis of the stationary tackle sheave arrangement perpendicular to the axes of the lower sheaves. By this construction, site pull on the sheave flanges is eliminated and the excessive wear resulting therefrom is obviated.

The especial advantages and further objects of the invention will be made evident hereinafter.

Referring-to the drawings which are for illustrative purposes only:

Fig. 1 is a vertical section through a crown block embodying the features of my inventionythis section being taken as indicated by the line 1-1 ofFig. 2.

' Fig. 2 is a vertical section taken as indicated by the line 2- 2 of Fig; 1.

3 is a diagramniatic view showing the crown block in use on a derrick.

Fig. 4. is a fragmentary sectional view showing the manner of rigging the block and tackle. Fig. 5 is adiagrammatic perspective view showing the manner in which the idler sheave may be employed.

As shown inFig. 3 of the drawing, it is customary to employ the construction of a drilling derrick, four inwardly sloping legs 11 which'are interconnected and braced by girts 12 and struts 13. At the top of the structure is a square frame work commonly term-ed the water table 15,. consisting of water table beams 16 which define a substantially square opening at the top of the derrick and in which the crown block is customarily placed. As shown in Figs. 1 and 2, my crown block'consists of a lower frame work 18 and an upper frame work 19, which are horizontally disposed. The lower frame work 18 preferably employs apair of beam members which are equipped for securement to the water table beams 16. In wood derrick construction, these water table beams generally consist of 12-X112timbers and the beams 18 are notched at the ends as indicated at 21 so that the central portion of the beams will extend down into the water table opening. Flanges 22 are secured to the webs 23 of thebeams either hy welding or by, the use of clips to provide ample bearing on the wa ter table beamslti. The beams 18 are placed fairly close together and support therebetween on shafts 2 1 and 25 the lower sheaves 26 and 27., these sheaves being disposed in the samevertical plane and being" located on each side of the central axis of the derrick so that when ropes or-cables 28 and 29- are run thereover, the downwardly extended portions thereof hang substantially in'the center of the; derrick as shown at 30 in Fig: 3. The shafts 21 and 25 extend, through openings 81 in the webs 23 of the beams 18 and are supported in bearing blocks 32. The left ward end of the shaft 24 as shown in Fig. 1 is extended sutliciently to receive a small sheave In view of the fact that it is preferable to employ a large diameter sheave in the positions 26 and 27 so that the bend of the cable or rope will not be acute, the sheaves 26 and 27 may be 30 inches in diameter which would require a beam 18 of substantially 20 inches in depth.

In positions parallel to the beams 18, beams are placed on the water table beams as shown in Fig. 1, and across the top of the beams 18 and is placed the upper frame work consisting; o't bean 37 and bracing; members 38. These beams 37 are separated at a distance to accon'imodate the number of sheaves 4.0 which are arranged upon a. shaft ll to form a stationary tackle sheave arrangement 39. In the drawings. live sheaves 4:0 are shown, it being understood that a greater or lesser number may be employed as the conditions may require. The shaft 41 is flattened, at the ends thereof as in: dicated at 43 to provide a stable bearing upon the upper flanges of the beams and is secured in place by U clamps ist. The beams 37 are disposed at right angles to-the beams 18 and 35 thus disposing the sheaves lO crosswise relative to the sheaves 26 and 27. As shown in Fig. 3, the sheaves 26 and 27 are aligned with the calf wheel 17 and bull wheel 48 which in turn are arranged to be driven from the band wheel 50. The sheave 26 may be employedto receive a rope from the calf wheel or may receive the sand line which is wound upon the sand reel. 52. The hull wheel 48 isemployed to receive the cable 29 which extends over the sheave 27. The

rotary draw works indicated in Fig. 8 is placed to the side of the bull wheel and call wheel, and the rotational axesof the rotating parts of the rotary draw: workslie parallel to a vertical plane which is perpendicular to the axes of rotation of the alf wheel, and; bull wheel. The stationary tackle sheave arrangement 39 being disposed crosswise of the sheaves 26 and 27, rotates in'plane with the rotary draw works so that the rope in Fig. 4' will extend directly down to the draw works and will not be drawn from the end sheave of the tackleblock at an angle which will cause wear on one of the sheave flanges. As shown in Fig. 4.. the ropes (31 which extend from the sheaves 10 to the suspended stationary tackle sheave arrangen'ient 62 pass downwardly upon each side of lll10:Sl1ttVGS 26 and 27 and the beams 18. thus centralizing the. suspended; block (i2 directly above the well which is being drilled. j

It will be recognized that in the arrangcment of sheaves employed in my device, all of the separate hoisting members which are to operate through the well casing fall centrally within the derrick; This feature is particularly valuable as thereby much effort is saved due to relief of the necessity of guiding the lifted members concentrically w'thin the derrick.

As shown in Fig. 5, the sheave 33 being u )011 the shaft 2st extends in a plane relatively perpendicular to the end sheave $0 of the stationary tackle sheave arrangement 39 so that one end of the rope indicated at in Fig. -l may be extended down to the drum of the calf wheel 47 as indicated at (57, this rope extending over the sheave 33 in the manner shown, thus preventing a side pull on the flange of the end sheave d0. This arrangen'ient is particularly desirable in the handling of casing and drill pipe as a pre 'aution against sticking of the pipe or casing due to stoppage of the rotary draw works resulting from breakage, as sometimes occurs. In case of trouble in the draw works, the using may be kept in motion, through the winding of the end of the rope which extends to the calf wheel, which calf wheel is driven from the band wheel which has a power source entirely separate from the rotary draw works. In Fig. 5, the relative disposal of the shafts 24c and ll. the calf wheel IT and the drum (SS) of the draw works 55 is shown. thus plainly indicating the cooperation between the s parate sheaves and the separate drums with which they are employed.

Although but two sheaves 26 and 27 are shown in the lower frame work, 't is to be understood that other sheaves may be supported therein for promiscuoushoisting duty as desired, without departing from the principles of the invention. A very important feature of the invention resides in the removability of the upper frame 19 which carries the stationary tackle sheave arrangement from the lower frame 1? by merely removing bolts 70. The heavy strains encountered in rotary drilling due to the heavy weight of the pipe and easing which must be carried requires a massive construction of the stationary tackle sheave arrangement. After the casing has been set and the well placed in production, need for heavy lifting past. T he sheaves carried in the lower frame work 17 are ample for the handling of tubing and the ordinary lifting which is to be done around a producing well. The stationary tackle sheave arrangement 39 therefore may be removed and employed in the drilling of another well. this removal of the stationary tackle sheave arrangement beiig.accomplished without difhculty or without dismantling of the permanent members of the crown block.

I claim as my invention:

1. In a crown block, the combination of: lower sheave means; members supporting said lower sheave means, arranged for installation in a derrick top; supporting structure extending upwardly from said members: and upper sheave means supported above said lower sheave means by said structure. the upper sheave means being disposed in a vertical plane substaiitiab ly perpendicular to the plane of said lower sheave means.

2. In a crown block, the. combination of: lower sheave means; members supporting said lower sheave means, arranged for installation in a derrick top; removable supporting structure extending upwardly from said members; and upper sheave means sup ported above said lower sheave means by said structure, the upper sheave means being disposed in a vertical plane substantially perpendicular to the plane of said lower sheave means.

3. In a crown block construction for oil derricks. the combination of: a pillow block; a pair of lower sheaves mounted to rotate about different axes in said pillow block; a pair of brackets extending upward from said pillow block; and a plurality of upper sheaves mounted to rotate bet-ween said brackets about a single axis disposed substantially at right angles to the axes of said lower sheaves.

at. In a crown block construction, the combination of: a frame work; two lower horizontal parallel shafts supported in said frame work; two lower sheaves, each mounted to turn about the axis of one of said shaf said sheaves being situated in the same vertical plane and on opposite sides at the center of the derrick; and a small lead-oil sheave also mounted on one of said lower shafts.

5. In a crown block construction, the combination of: a frame work; two lower hori zontal parallel. shafts supported in said frame work; two lower sheaves, each mounted to turn about the axis of one of said shafts; and a small lead-off sheave also mounted on one of said lower shafts.

(3. In a crown block construction, the combination of: a frame work; two lower horizontal parallel shafts supported in said frame work; two lower sheaves, each mounted to turn about the axis of one of said sha said sheaves being situated in the same vertisal plane and on opposite sides of the center of the derrick: a small lead-oil sheave also mounted on one of said lower shafts: upper members mounted in said frame: an upper shaft supported in said upper members and extending in a direction substantially at right angles to said lower shafts in a horizontal plane substanially parallel to the plane of said lower shafts; and a plurality of upper sheaves mounted on and turning freely about the axis of said upper shaft.

'7. In a crown block construction, the combination of: a frame work: two lower horizontal parallel shaft-s supported in said lit) frame Work; two lower sheaves, each mounted to turn about the axis of one of Said shafts; a small leadbli sheave also mounted on one of saicl. lower shafts; upper members mounted insaicl frame; an upper shaft supported in said upper members and extending in a direction substantially at right angles to said lower shafts in a horizontal plane substantially parallel to the plane of saicl lower shafts; and a plurality of upper sheaves mounted on and turning freely about the axis of said upper shaft.

In testimony whereof, I'haVe hereunto set my hand at Los Angeles. California, this 26th day of November, 1923.

EDlVIN O. BENNETT. 

